Portaudio DLLs (release build) for Windows

* Used PortAudio v19 from http://www.portaudio.com/download.html
* Used cmake to create project files for VS2012 [Version 11.0.60610.01 Update 3] (32bit and 64bit)
* No DirectX backend support yet [if required, I need to set up directx
first]
* Added preprocessor macro PA_WDMKS_NO_KSGUID_LIB to fix build
(http://code.google.com/p/dolphin-emu/issues/detail?id=5662)
* Renamed portaudio_x86.dll to portaudio32.dll and portaudio_x64.dll to portaudio64.dll.

Feel free to test these DLLs. Please tell me if DirectX support is really needed, as setting up DirectX is a bit more difficult ;)